(i) Field of the Invention
The invention relates to a particularly long-chain inulin and its preparation from artichoke roots, to its use in foodstuffs and cosmetic preparations and to foodstuffs and cosmetic preparations which comprise the particularly long-chain inulin.
(ii) Description of the Related Art
The demand for foodstuffs which contain little fat and more natural raw materials has increased greatly in recent decades. Many substances have already been proposed as substitute for fats, such as products based on carbohydrates or protein or synthetic fat substitutes such as sugar polyesters of fatty acids. However, these always have disadvantages such as a low thermal stability, an unsatisfactory “mouth feel” or an unwanted effect on people or the environment.
It has been known for a long time that inulin is suitable for use in food products. Inulin has a low energy value available for humans and thus use of inulin as fat substitute ensures a large reduction in the calorific value of the final product. In addition, inulin is used as prebiotic addition and bulking agent in foodstuffs.
Inulin is a polysaccharide belonging to the fructan group. It consists of a beta-2-1-linked chain of fructose molecules, and this chain may have an alpha-D-glucose unit at the reducing end. Inulin occurs in economically recoverable amounts in various plants such as, for example, chicory roots, Jerusalem artichoke and dahlia tubers. The average chain lengths of the various inulins and their physicochemical properties differ from plant species to plant species.
The inulins employed to date in the foodstuffs sector are not entirely satisfactory in their processing properties such as, for example, viscosity in aqueous pasty form, thermal stability and stability to acid, emulsifiability and water-binding capacity.
There is in addition a need for inulins with improved fermentation properties and a greater prebiotic effect.
A further problem is that on extraction of inulin with hot water from the plant tissue the extract contains besides the polymer crude inulin also monosaccharides such as glucose and fructose, disaccharides such as sucrose and fructooligosaccharides (DP 3-10). These by-products (mono- and disaccharides, fructooligosaccharides (DP 3-10) may interfere with further processing of the inulin. For example, mono- and disaccharides are undesired in the manufacture of dietetic food products. The sweet taste of the mono- and disaccharides and fructooligosaccharides (DP 3-10) interferes with certain applications in the food products sector. Fructooligosaccharides (DP 3-10) may, because of their hygroscopicity and tackiness, interfere greatly with the use of crude inulin in food products both during processing and during storage. During further processing of the crude inulin, for example by chemical derivatization, mono- and disaccharides and fructooligosaccharides (DP 3-10) may lead to undefined mixtures of products which can be purified only by costly methods or not at all. In addition, a high proportion of reducing sugars has the disadvantage that in thermal processes in the presence of amino compounds there may be unwanted browning reactions, the formation of off-flavors and the production of acrylamide (Maillard reaction).